July 31 (Reuters) - Canada’s Shopify Inc reported another quarter of slowing growth in a key metric that overshadowed a surprise adjusted quarterly profit, sending the company’s shares down about 6 percent.

Shopify’s shares have had a strong run this year as investors bet on rising demand for the company’s software, which helps clients build and run their online stores. The company’s Toronto-listed shares have gained 51 percent, while U.S. shares are up about 39 percent this year.

The company on Tuesday said gross merchandising volume (GMV), or the total sales by all vendors using Shopify’s software, rose 56 percent in the second quarter, compared with a 74 percent jump a year earlier. It had slipped to 64 percent in the first quarter from 81 percent a year earlier.

“There are high expectations from shareholders for the company to grow faster, as reflected in the stock’s strong year-to-date performance. Going forward, the potential for a re-acceleration in growth will depend on its initiatives, including Shopify Plus and international expansion,” said D.A. Davidson & Co analyst Thomas Forte.

“The market is responding to the deaccelerated growth rate.”

Growth in the company’s monthly recurring revenue, another widely watched number, declined to 49 percent from 64 percent a year earlier.

Shopify’s traditional client-base has been small- and medium-size businesses, but the Ottawa-based company has been spending to attract big brands.

Such efforts seem to be paying off. Share of Shopify Plus, its higher-margin product aimed at enterprises, accounted for 23 percent of the company’s monthly recurring revenue, up from 18 percent a year earlier.

Total subscription revenue in the reported quarter jumped 54.6 percent, powering a 61.5 percent surge in total revenue to $245 million.

However, the company’s investments in research and marketing drove a 63.2 percent rise in expenses to $167.7 million.

Shopify is also tapping international markets, launching Shopify Payments in Japan, taking the number of countries where the facility is available to eight.

The company’s net loss widened to $24 million from $14 million.

Excluding certain items, the company posted a profit per share of 2 cents, while analysts on average estimated a loss of 3 cents per share, according to Thomson Reuters I/B/E/S.

U.S.-listed shares were down 6 percent at $139, while the Toronto-listed shares slipped 5 percent to C$181.34. (Reporting by Akshara P in Bengaluru; Editing by Shounak Dasgupta and Sriraj Kalluvila)